Time-of-flight based neutron background reduction in secondary-electron-bremsstrahlung imaging for in-vivo range verification of proton therapy: a Monte Carlo study
Time-of-flight based neutron background reduction in secondary-electron-bremsstrahlung imaging for in-vivo range verification of proton therapy: a Monte Carlo study
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用于质子治疗体内范围验证的二次电子轫致辐射成像中基于飞行时间的中子本底降低：蒙特卡罗研究
DOI：
10.1088/1748-0221/18/02/c02041
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发表时间：
2023
影响因子：
1.3
通讯作者：
Kawachi N.
中科院分区：
文献类型：
--
作者：
Yabe T.;Yamaguchi M.;Tsuda M.;Nagao Y.;Kawachi N.
在质子治疗中，范围验证对于监测患者体内布拉格峰的位置非常重要。二次电子轫致辐射（SEB）成像是一种很有前景的质子射程验证方法。不幸的是，专用伽马相机测量的 SEB 图像包含中子引起的背景以及 SEB 计数。为了提高SEB成像中距离验证的准确性，我们建议应用飞行时间（TOF）方法来减少SEB测量图像中的中子背景。 SEB 和中子的产生和传输通过蒙特卡罗模拟进行计算。将质子笔束照射到水体模上，然后通过在探测器上刻划获得 SEB 和中子的时间谱和剖面。中子总数大约是 SEB 的 10 倍，并且随着质子能量的增加而增加。 TOF方法为SEB的TOF谱选择一个时间窗口，将中子背景降低了97%以上。我们得出的结论是，TOF 方法可以显着降低中子背景并提高 SEB 成像中质子范围验证的准确性。
In proton therapy, range verification is important to monitor the location of the Bragg peak within the patient's body. Secondary-electron-bremsstrahlung (SEB) imaging is a promising method of proton range verification. Unfortunately, the SEB images measured by the dedicated gamma camera contain neutron-induced backgrounds as well as the SEB counts. To improve the accuracy of range verification in SEB imaging, we propose to apply a time-of-flight (TOF) method to reduce neutron background in measured images of SEB. The SEB and neutron generation and transport were calculated by a Monte Carlo simulation. Proton pencil beams were irradiated to a water phantom and then the time spectra and profiles of SEB and neutron were obtained by scoring on a detector. The total count of neutrons was approximately 10 times higher than that of SEB and increased with higher proton energy. The TOF method, selecting a time window for the TOF spectrum of SEB, reduced the neutron background by more than 97%. We concluded that the TOF methods can dramatically reduce neutron background and improve the accuracy of proton range verification in SEB imaging.